From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: Xen PCI passthru supported reset methods (d3d0, FLR, bus reset, link reset) Date: Mon, 17 Sep 2012 15:15:57 -0400 Message-ID: <20120917191556.GB18552@phenom.dumpdata.com> References: <20120917113833.GH8912@reaktio.net> <50570EA7.8060509@student.chalmers.se> <20120917123205.GJ8912@reaktio.net> <1347885774.14977.64.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <1347885774.14977.64.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: "xen@lists.fedoraproject.org" , Robin Axelsson , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On Mon, Sep 17, 2012 at 01:42:54PM +0100, Ian Campbell wrote: > On Mon, 2012-09-17 at 13:32 +0100, Pasi K=E4rkk=E4inen wrote: > > On Mon, Sep 17, 2012 at 01:51:03PM +0200, Robin Axelsson wrote: > > > = > > > There is one thing I wonder though when it comes to PCI passthrough: > > > = > > > Can Xen reset hardware through the d3d0 in the ACPI interface and/or > > > through a 'bus reset' or a 'link reset'? Or can it reset hardware > > > that is marked for passthrough only through FLR? > > > = > > > For details see e.g. > > > http://www.vmware.com/files/pdf/techpaper/vsp_4_vmdirectpath_host.pdf > > > > > = > > I added xen-devel to the CC-list. > > Hopefully someone there can reply this question. > = > With a pvops dom0 Xen resets devices by writing to its "reset" node in > sysfs so it will reset the device using whatever method the dom0 kernel > supports for that device. And if you use Xen PCI-back it has this enabled so you don't even need the 'reset' functionality. > = > The version of Linux I have to hand has, in __pci_dev_reset, calls to > the following in this order and stops after the first one which > succeeds: > * pci_dev_specific_reset (AKA per device quirks) > * pcie_flr > * pci_af_flr > * pci_pm_reset > * pci_parent_bus_reset > = > See drivers/pci/pci.c in the kernel for more info. > = > IIRC classic Xen kernels had similar code in pciback, although I don't > know which specific sets of actions or in which order they were tried. > = > Ian. > = > = > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel > =